Apparatus for continuously processing viscous liquids and masses

ABSTRACT

An apparatus for continuously processing viscous liquids and masses has axially parallel satellite shafts (23) disposed in a ring within a housing (4) and driven in the same direction which bear meshing processing means (24) and are driven by a central shaft (17) bearing central gearwheels (19; 20). Each satellite shaft (23) bears two axially spaced coaxial pairs of pinions (27; 34), one pinion (28; 36) of each pair of pinions engaging a central gearwheel (19; 20) and the other pinion (29; 35) engaging the internal toothing of an annular gear (5; 9) fixed on the housing. The toothings of the pinions (28, 29) of one pair of pinions (27) are formed with a module which results in an integral number of teeth on the central gearwheel (19) or on the internal toothing of the annular gear (5) from satellite shaft (23) to satellite shaft (23). The central shaft (17) is supported on the annular gears (9, 10) only via the central gearwheels (19, 20) and the pinions (28, 29; 35, 36).

The present invention relates to an apparatus for continuouslyprocessing viscous liquids and masses, in particular molten plasticmasses and high-molecular polymers, having a number of axially parallelsatellite shafts disposed in a ring within a housing and driven in thesame direction via associated pinions, said shafts bearing processingmeans engaging each other on adjacent satellite shafts and spreading thematerial to be processed in a thin layer in certain areas, a centralshaft disposed in the center of the space surrounded by the satelliteshafts and driven axially parallel to the satellite shafts, said centralshaft bearing at least one driving gear so as to rotate therewith, thesatellite shafts being coupled in geared fashion via their pinions withthe central driving gear and with the internal toothing of at least oneannular gear fixed on the housing in such a way that when the centralshaft rotates the satellite shafts perform a common revolving motionabout the central shaft, and feeding and removing means for introducingthe material to be processed into the range of action of the processingmeans on the inlet side and removing it therefrom on the outlet side.

so-called thin-layer multishaft reactors have been developed for examplefor homogenizing and degassing high-molecular molten polymer masses(DE-C 3 030 541) that have the fundamental advantage over conventionalso-called screw-type extruders that they make do with economically andtechnically realizable working lengths while having high degassing powereven for long sojourn times of the material to be processed.

These known multishaft reactors work with a number of shafts disposed ina ring and bearing the processing tools for example in the form ofkneading plates. The processing tools of adjacent shafts mesh with oneother, the viscous material being spread into thin layers again andagain when passing through the narrow gaps limited by the processingtools. Multishaft reactors of this design are therefore very efficientin terms of process engineering. The shafts are driven via a distributorgear located outside the vacuum space. However it has turned out thatthis distributor gear and the system necessary for sealing the manyshafts from the vacuum are technically elaborate and expensive, inparticular if the shafts are to be heated.

Of simpler construction is a developed embodiment (DE-C 4 001 986) whichdispenses with a distributor gear on the outside and drives the shaftsvia a planet gear whose gearwheels are shifted into the working area.Since the gearwheels are lubricated by the material to be processed thisconstruction is only applicable for material that permits such gearwheelaction without being damaged in its structure or composition.Furthermore, with this type of construction the individual planet shaftsare supported at both ends against the housing via bearings, which meansthat the reactor can only be formed with one working chamber. Inparticular if the reactor is disposed horizontally this limits thelength of the working area (smaller than about 15 times the shaftdiameter) because the unavoidable sagging of the shafts otherwise leadsto difficulties which cannot be solved with economically reasonableeffort. These difficulties result from excessive reversed bending stresson the shafts, the danger of the particular bottom shafts runningagainst the housing, the less favorable engagement conditions for thegearwheels and processing tools and the like. Leaving aside thatunfavorable lubricating conditions arise for the gearwheels of theplanet gear, and no shaft heating can be provided so that a functionallydisadvantageous temperature response might come about in the gearing,the planet gear used, a three-link gear, can only be formed with onetoothing module for the central gear and the annular gear on the housingside because the pinions seated on the planet shafts mesh in one planeboth with the toothing of the central wheel and with the internaltoothing of the annular gear.

Because the spirals disposed on the planet shafts to form the processingmeans presuppose certain regularities between the outside diameter ofthe worm, the core diameter of the worm and the resulting axialdistances, the pinions can only be fastened on the planet shaftsnonpositively. This means that during assembly the individual planetshafts must be adjusted with great care in their angular positionrelative to the particular corresponding pinion. Proper functioning ofthe reactor thus depends to a considerable degree on the skill of theassembly staff, which is inexpedient. A positive connection of thepinions with the planet shafts could only be had with very greattechnical effort and is therefore out of the question.

The invention is therefore based on the problem of remedying this andproviding a thin-layer multishaft reactor characterized by a reliable,easily produced and assembled drive for the shafts bearing theprocessing means, with a proper, gentle supply of material to theprocessing means on the satellite shafts.

To solve this problem the apparatus stated at the outset ischaracterized according to the invention in that each satellite shaftbears at least two coaxial pairs of pinions, one pinion of each pair ofpinions engaging only a central gearwheel and the other pinion engagingonly the internal toothing of an annular gear, and the pairs of pinionsbeing spaced apart axially.

This makes it possible to design the pairs of toothing between theparticular central gearwheel and the pinion side, on the one hand, andbetween the particular annular gear and the pinion side, on the otherhand, for optimal engagement conditions in each case independently ofeach other. It in particular opens up the possibility of providing bothpinions of at least one pair of pinions, in particular the pair ofpinions located on the inlet side of the material to be processed, withopposed helical toothings associated with corresponding toothings on theparticular central gearwheel or on the particular annular gear.

This formation of the toothings on the pairs of pinions causes axialforces acting on the central shaft and the satellite shafts to beremoved via the central gearwheels and the pinions directly into theannular gears fixed on the housing. The central shaft and the satelliteshafts are automatically centered relative to each other and to thehousing. This makes it possible to dispense with a separate axial andradial support of these shafts and arrange the assembly such that thecentral shaft and/or the satellite shafts are supported axially andradially on the annular gears only via the central gearwheels and thepinions.

Since the toothings of the annular gear and the central gearwheel ofeach pair of pinions can be designed for optimal engagement conditionsindependently of each other, as mentioned, the assembly can beadvantageously arranged such that the toothings of the pinions of onepair of pinions are each formed with a module that results in anintegral number of teeth on the central gearwheel or on the internaltoothing of the gearwheel from satellite shaft to satellite shaft. Oneneed thus make no compromises with respect to the toothing modules, asis imperative when using simple planet gears for such multishaftreactors.

It is of special advantage in this connection if the pinions areconnected with the satellite shafts so as to rotate therewith bypositive connecting means, which expediently have a toothing with amodule resulting in an angular pitch whose integral multiple correspondsto the angular pitch between two satellite shafts.

This toothing makes it unnecessary to perform elaborate adjusting workduring assembly of the satellite shafts, and permits the same pinions tobe used for all satellite shafts. Based on the cross section through thehousing of the apparatus the radial reference axes of cooperatingprocessing members on adjacent satellite shafts can be brought into theparticular correct position in simple fashion with both a single-startand a multi-start construction, it being possible to use single- anddouble- or multi-start profiles for the processing means along theapparatus simultaneously.

In the area between the pairs of pinions on the inlet side and theoutlet side the satellite shafts can bear at least one further pair ofpinions having a corresponding central gearwheel and a correspondingannular gear associated therewith. This formation permits use ofsatellite shafts with virtually any desired length in accordance withthe conditions of the particular case of application, their length beinglimited solely by economic considerations or the space required by theapparatus. The satellite shafts can also be formed with a comparativelysmall diameter, if required, because the driving torque can beintroduced into the satellite shafts at several places spaced apartaxially.

Since the pinions of each pair of pinions are helical toothed withopposed pitch and axial forces acting on the satellite shafts are takenup and removed into the annular gear on the housing side, the satelliteshafts can also be of multipart design in apparatus with greater axiallength, the shaft parts being interconnected so as to rotate with oneanother by simple coupling means. These coupling means are expedientlydisposed directly before the particular pair of pinions in the directionof flow of the material to be processed.

To compensate the resistance to flow in the area of the pairs of pinionsto be overcome by the material as it flows through, without having toincrease the pressure of the material in the apparatus as a whole, it isadvantageous if the pinions are preceded by conveying members disposedon the satellite shafts, for example in the form of short screwconveyors. With multipart satellite shafts the abovementioned couplingmeans can be simultaneously formed therein, resulting in a furthersimplification of the construction.

If the satellite shafts are supported axially on the inlet side againstthe corresponding annular gear fixed on the housing via a pair ofpinions with opposed pitch of the helical toothing in the explained way,the other pair of pinions on the outlet side is expediently providedwith a spur toothing, as are the corresponding central gearwheel and thecorresponding annular gear, so as to automatically compensate thermallyinduced changes in length of the satellite shaft for example. The sameapplies to the individual shaft portions of divided satellite shafts.

Any further pairs of pinions disposed between the pairs of pinions onthe inlet and outlet sides are generally also formed with a spurtoothing.

The helical and/or spur toothed pairs of pinions are advantageouslypreceded and/or followed by conveying and/or baffle members for thematerial to be processed in order to overcome the resistance to flow ofthe toothings, on the one hand, and the counterpressure resulting fromthe subsequent processing means or discharge tools, on the other hand,if required.

In a preferred embodiment a baffle plate having passages for thematerial to be processed, which is coaxial with the central shaft andrevolves about the central shaft together with the satellite shafts, isdisposed between the pinions of at least one pair of pinions for eachsatellite shaft. This baffle plate advantageously bears axially directedpackings which substantially fill the wedge-shaped spaces betweenadjacent pinions and/or conveying members adjacent thereto and thecentral shaft as well as the enveloping housing or housing portion.These baffle plates onto the inside or the outside of the processingmeans seated on the satellite shafts, thereby ensuring proper separationof the thick-layer side and the thin-layer side and thus excellentdegassing conditions. At the same time the process section of theapparatus can be divided into several independent processing spaces, inparticular degassing spaces. For assembly reasons one then also uses thedivided satellite shafts described above. The packings prevent clearancespaces from forming in the wedges between the toothings where materialto be processed remains unprocessed and leads to disturbances in thefunctioning of the apparatus and to impairment of the quality of thematerial to be processed.

The packings can be covered at least on the face pointing toward theinlet side of the material to be processed at least partly by freelyrotatable ring-shaped cleaning plates which are coaxial with the centralshaft and driven in frictional engagement.

Since the satellite shafts are supported axially on the inlet side bythe pinions of the pair of pinions having opposed helical toothing,without any separate axial bearings being required in the cover on theend face of the housing, this fact can be utilized for a very simpleeasy-to-service supply of material to be processed to the satelliteshafts and their processing means. The feeding means for the material tobe processed advantageously have for this purpose at least one ringchannel connected with an inlet, whereby said channel communicates withthe satellite shafts in the area of their faces and can be formed with adepth decreasing increasingly from the inlet.

Because the central shaft, with the stated formation of its pair ofpinions on the inlet side, also requires no separate axial bearing inthe area of the cover on the end face of the housing, the central shaftcan also be sealed from the housing effectively with simple means. Forthis purpose the seal of the central shaft has a cooling ringsurrounding it so as to form an annular gap and having means for coolingand/or heating associated therewith, the annular gap being subjected tomaterial to be processed which can be held at a temperature below itsmelting point by the cooling ring. The cooling ring can have ring-shapedcoaxial grooves on the shaft side, while in the area of the cooling ringor in the vicinity thereof the central shaft can bear conveying meansfor supplying the annular gap with material to be processed whichcommunicate with its feeding means. The material to be processed is thusused directly as sealing means, whereby a continuous or periodic rinsingof the annular gap with free-flowing material to be processed can alsobe performed at the same time via a corresponding connection with thering channel of the feeding means for the material to be processed.

These conveying means can be formed for example by a conveying threadwhich is supplied with material to be processed via a corresponding sidechannel.

Depending on the type of material to be treated and the temperaturerange in which this treatment is to be performed, it may be necessary tosupply the material with heat while it passes through the apparatus. Forthis purpose the central shaft can be formed as a hollow shaft and beheatable by heating media inserted or passed therein, for exampleinserted rod-shaped heating elements or thermal oil flowing through.

The drawing shows embodiment examples of the object of the invention.

FIG. 1 shows a detail of an apparatus according to the invention inaxial cross section from the side,

FIG. 2 shows a portion of the apparatus of FIG. 1 on the inlet side ofthe material to be processed in a cross-sectional view according to FIG.1 and on a different scale,

FIG. 3 shows the intermediate portion of the apparatus of FIG. 1illustrating the degassing chamber in a corresponding representation andon a different scale,

FIG. 4 shows the portion of the apparatus of FIG. 1 on the outlet sideof the material to be processed in a corresponding cross-sectional viewand on a different scale,

FIG. 5 shows the apparatus of FIG. 1 in cross section from the topillustrating in sectors the particular cross-sectional views on variouscutting lines AB to WX of the apparatus of FIGS. 2, 3, 4, 16,

FIG. 6 shows a detail from the representation of FIG. 5 illustrating theserration, on a different scale,

FIG. 7 shows the apparatus of FIG. 1 cut along line YZ in FIG. 3 fromthe top and on a different scale,

FIGS. 8 and 9 show a baffle plate of the apparatus of FIG. 1 inperspective and from above and below,

FIG. 10 shows the distributing plate of the apparatus of FIG. 1 with thecorresponding sealing disks in a perspective partial view and on adifferent scale,

FIG. 11 shows a perspective schematic detail of the wedge areas betweenthe satellite shafts, the central shaft and the surrounding housing on ascale corresponding to FIG. 9,

FIG. 12 shows two cleaning plates of the apparatus of FIG. 1 in aperspective partial view,

FIG. 13 shows a schematic representation of the frictionally engageddrive conditions for the cleaning plates of FIG. 11,

FIG. 14 shows a baffle plate of the apparatus of FIG. 1 with one-sidedpackings in perspective and on a different scale,

FIG. 15 shows two different embodiments of the apparatus of FIG. 1 witha different number of axially joined processing areas, each in axialcross section and from the side, and

FIG. 16 shows an intermediate portion of an apparatus according to FIG.13 provided with a radial support of the satellite shafts, in axialcross section from the side and on a different scale.

The apparatus shown in FIG. 1 serves to homogenize and gas or degas aviscous liquid or mass, for example a molten high-molecular polymermass. It has cylindrical housing 1 which can be disposed horizontally orvertically and is sealed vacuum-tight by cover plate 2 on the inlet sideof the material to be processed and by cover 3 on the outlet side of thematerial. It comprises cylindrical housing jacket 4 followed on theinlet side by coaxial internal toothed first annular gear 5, coaxialspacer ring 6 and housing ring 7 on which cover plate 2 is placed.

On the outlet side housing jacket 4 is connected with second housingring 8 which is followed by second internal toothed annular gear 9, thensecond spacer ring 10 and then third housing ring 11 which borders oncover 3. Rings 5, 6, 7 on the inlet side and 8, 9, 10, 11 on the outletside are braced in the correct position together with cover plate 2 orcover 3 by axially parallel tie rods (not shown) with each other andwith corresponding end flange 12 or 13 of housing jacket 4. Seal ringsdisposed on the interfaces, as indicated by way of example at 15, ensurea vacuum-tight seal. Electric heating elements 16 placed on the outsideof the housing permit housing 1 to be heated from the outside, the axialsubdivision of heating elements 16 into portions permitting a differentcontrol of the supply of heat over the axial length of the apparatus.However all housing portions can also be formed with a double jacket tobe tempered with thermal oil.

Coaxial central shaft 17 is pivoted in the housing. It bears cylindricalshaft jacket 18 extending between a pair of central gearwheels 19, 20connected with central shaft 17 so as to rotate therewith, one beingdisposed in the area of spacer ring 6 on the inlet side and the other inthe area of spacer ring 10 on the outlet side.

Central shaft 17 is formed as a hollow shaft with through bore 190 whichis sealed vacuum-tight by screw cap 200 on the outlet side and containsan electric rod heater indicated at 21 whose main feed line is ledthrough onto slip rings 22 on the inlet side.

Twelve axially parallel satellite shafts 23 surrounded by the housingare disposed in a ring about central shaft 17 in the way apparent inparticular from FIGS. 5, 7. In the embodiment example shown they areeach of multipart design and bear processing means in the form ofspirals 24 over a portion of their longitudinal extent correspondingapproximately to the length of housing jacket 4. Instead of spirals 24satellite shafts 23 could also be equipped with other processing tools,for example in the form of kneading plates as are known from DE-C 3 030541. Combinations of different processing tools with each other and withspirals are also possible.

The diameter of spirals 24 is selected such that ridges 25 extend with asmall working gap of about 0.4 mm as far as the inside wall ofcylindrical housing jacket 4 on the outside, on the one hand, and as faras cylindrical shaft jacket 18 on the inside, on the other hand. Theworking annular gap is selected to be so small that an effective axialseal is present on housing jacket 4 and shaft jacket 18 duringoperation.

Placed on cylindrical portion 26 of satellite shaft 23 on the inlet sideis pair of pinions 27 comprising pinions 28, 29 which are connectedpositively with particular satellite shaft 23 so as to rotate therewith.

Upper pinion 28 located on the inlet side of the material to beprocessed in FIG. 2 engages central gearwheel 19, while second pinion 29meshes with the internal toothing of annular gear 5 fixed on thehousing. As indicated in FIG. 2, pinions 28, 29 bear a helical toothingwith an opposed pitch, associated with a corresponding helical toothingon central gearwheel 19 or annular gear 5.

The two opposed helical toothings on pinions 28, 29 of pair of pinions27 together form a double helical toothing. They cause axial forcesacting on central shaft 17 and satellite shafts 23 to be removed via thetoothings directly into annular gear 5 fixed on the housing, asindicated in FIG. 2 by a path shown at 30 for the flux of the axial andradial forces. At the same time satellite shafts 23 are automaticallycentered radially by these toothings, while central shaft 17 withcentral gearwheel 19 is likewise supported radially via pinions 28, 29on annular gear 5 fixed on the housing. No separate radial or axialbearings are therefore necessary in the area of housing cover 2 forcentral shaft 17 and/or satellite shafts 23.

Helical toothings of pinions 28, 29 of pair of pinions 27 are designedwith different modules which are selected so as to result in each casein optimal engagement conditions with the spur toothing of centralgearwheel 19 or the internal toothing of annular gear 5. The modules areselected so that an integral number of teeth results on centralgearwheel 19 or on the internal toothing of annular gear 5 fromsatellite shaft 23 to satellite shaft 23. This is illustrated in FIGS.5, 6 in the sectors corresponding to sections IJ and MN: the toothingportion located between two adjacent satellite shafts 23 has five teethwith central gearwheel 19 and eight teeth on annular gear 5.

For rotationally firm positive connection of pinions 28, 29 withparticular satellite shaft 23 the latter is provided in cylindrical area26 with axial serration 31 (FIG. 6) which engages a correspondinginternal serration on the two pinions. The module of serration 31 isselected so as to result in an angular pitch of the toothing whoseintegral multiple corresponds to the angular pitch between two adjacentsatellite shafts 23. In the present case the angular pitch between twoadjacent satellite shafts 23 is 30° C. (360°: 12 shafts), while theangular pitch of serration 31 with 36 teeth is 10° C.

Since spirals 24 of satellite shafts 23 can be double, by the way, thenumber of teeth of serration 31 must additionally be divisible by four.

The explained design of serration 31 and the pinion toothings permitspinions 28, 29 to be slipped on serration 31, during assembly, in anangular position relative to satellite shafts 23 such that individualsatellite shafts 23 always maintain their correct mutual spatialassociation when revolving about central shaft 17, as apparent from FIG.7. That is, the radial reference axis of spirals 24 indicated at 32 inFIG. 7 retains its spatial alignment. This ensures properly invariableprecise engagement conditions for adjacent spirals 24 in each case. Atthe same time one can use pinions 28, 29 of like design for allsatellite shafts 23, merely slipping them on serration 31 of satelliteshafts 23 (which are also of like design) in a different angularposition.

As seen in particular in FIG. 4, second pair of pinions 34 is placed oncylindrical end portion 33 of satellite shafts 23 on the outlet side ofthe material to be processed. This pair comprises coaxial pinions 35, 36which are for example coupled positively with the particular satelliteshaft via a serration corresponding to serration 31 (FIG. 6). Pinions35, 36 bear a spur toothing for engaging a corresponding spur toothingon the inside of annular gear 9 or on the outside of central gearwheel20.

The spur toothings permit a certain axial mobility of satellite shafts23 and central shaft 17 in this outlet area so that, for example, slighttemperature-induced changes in the length of these shafts arecompensated without obstruction. At the same time central shaft 17 andsatellite shafts 23 are supported via pinions 35, 36 radially on annulargear 9 fixed on the housing so that it is also unnecessary to disposeseparate axial or radial bearings in cover 3 on the outlet side of thematerial to be processed.

Between pinions 28, 29 of first pair of pinions 27 and between pinions35, 36 of second pair of pinions 34 there is in each case baffle plate37, whose structure can be seen in particular from FIGS. 8 and 9.

Circular cylindrical baffle plate 37 is formed as a ring plate withcoaxial cylindrical opening 38 which surrounds shaft jacket 18 with anarrow annular gap and extends on its outer circumference likewise witha narrow gap as far as the inner surface of spacer ring 6 (FIG. 2) or 10(FIG. 1). It is provided with axially parallel cylindrical through bores39 through which cylindrical portions 26 or 33 (FIGS. 2, 4) of thesatellite shafts extend. Inserted internal serrated ring bearings 40(FIG. 2) seal serration 31 (FIG. 6) and result in proper motionalconditions relative to the inside walling of bores 39.

Axially parallel flow channels 41 for the material to be processed arebored axially centered between adjacent axial bores 39 on a commoncircle coaxial with central opening 38. As seen in particular in FIGS.5, 6, flow channels 41 open between the disengaged toothings of pinions28, 29 or 35, 36 (FIGS. 2, 4) of adjacent satellite shafts 23,approximately at or near the place where the pinion toothings ofadjacent satellite shafts approach each other furthest.

Upright, axially parallel packings 42 are formed on the top andunderside of baffle plate 37, their faces lying in a common horizontalplane and the packings being laterally limited substantially byintersecting, axially parallel cylindrical surfaces. Packings 42 have across section such that they largely fill the wedges present on eachside of flow channels 41 between the toothings of the pinions of pairsof pinions 28, 29 or 36, 37 and corresponding central gearwheel 19 or 20as well as corresponding annular gear 5 or 9 fixed on the housing (FIGS.2, 4). For this purpose packings 42 extend as far as the circumferentialsurface of central shaft 17 at 46 so as to form a narrow annular gap, asbriefly explained for example with reference to FIG. 2, while at 47 theylikewise seal with a cylindrical surface so as to form a narrow annulargap from the inside cylindrical surface of spacer ring 6. At 48, 49 thecorresponding cylindrical surfaces of packings 42 are set back radiallyto make room for the toothing of central gearwheel 19 or annular gear 5.

The same applies to baffle plate 37 inserted in second pair of pinions34 (FIG. 4).

Baffle plate 37 firstly has the function of ensuring a regularcontrolled flow of material to be processed through particular pair ofpinions 27 or 34. Secondly, it prevents material from collecting in theareas between the pinions of central shaft 17 and the outer surroundinghousing portions, which is not conveyed further and thus solidifies,thereby jeopardizing the reliability of the whole apparatus in thecourse of time.

In the direction of flow of the material to be processed pairs ofpinions 27, 34 are preceded for each satellite shaft 23 by a conveyingmember in the form of screw conveyor 50 which is placed on serration 31of the shaft so as to rotate therewith. Screw conveyor 50 is formed as aworm sleeve into which corresponding serrated end piece 51 protrudes onthe inlet side, said end piece being centered by guide bush 52 relativeto cylindrical portion 26 of particular satellite shaft 23 and bearingon cylindrical head portion 53 distributing grooves 54 disposed in across (FIG. 5 section according to sector CD).

The constructional design on the outlet side of the material to beprocessed is fundamentally similar, as apparent from FIG. 4. The guidebush is again referred to as 52. The assembly is only such that secondscrew conveyor 50 is placed on each satellite shaft 23 behind pair ofpinions 34 in the direction of flow for conveying the processed materialinto outlet channel 55 leading to central discharge opening 56 in cover3.

Each satellite shaft 23 is formed as a hollow shaft; it containscontinuous tie rod 560 that is screwed to end pieces 51, 540 and bracesthe whole thing into a uniform shaft.

Screw conveyor 50 of each satellite shaft has associated baffle plate37a that is shown in FIG. 14 and has fundamentally the same structure asbaffle plate 37 (FIGS. 8, 9). The only difference is that packings 42aare disposed only on one Plane side of baffle plate 37a. Packings 42aare designed with their intersecting cylindrical surfaces limiting themlaterally in such a way as to surround screw conveyors 50 substantiallyover their axial extension, as indicated in FIGS. 2, 4. Flow channels41a for the material to be processed located on a common coaxial circleaxially centered between through bores 39a for cylindrical portions 33of satellite shafts 23 conduct the particular material conveyed by screwconveyors 50 either to pinions 28, 29 of first pair of pinions 27 or topinions 36, 37 of second pair of pinions 34. Only packings 42asurrounding end screw conveyor 50 placed on particular satellite shaft23 on the outlet side point toward outlet channel 55, so that materialflows through baffle plate 37a in the reverse direction here incomparison to the conditions with baffle plate 37a preceding pair ofpinions 34.

Baffle plate 37a preceding pair of pinions 34 on the outlet side resultsin the necessary back pressure for treatment of the material by spirals24, while packings 42a of baffle plates 37a fill the wedge spacesbetween central shaft 17 and the housing as well as the toothingspresent in this area, in the way explained above, in order to avoidclearance spaces in the flow path of the material.

Two coaxial cleaning rings 58 are placed on packings 42a of baffle plate37a preceding pair of pinions 34 on the outlet side. Inner cleaning ring58 is rotatably mounted on the circumferential surface of shaft jacket18, and the outer cleaning ring of greater diameter on the insidesurface area of housing jacket 4 (FIGS. 4, 12).

As indicated by the sketch in FIG. 13, cleaning rings 58 are driven infrictional engagement in the opposite sense of rotation when satelliteshafts 23 revolve about central shaft 17 because they are coupled byfrictional engagement with screw conveyors 50 on the outside or insideof the rotational axis of the particular satellite shaft. The functionof cleaning rings 58 is to eliminate clearance spaces in the areas ofthe transition between spirals 24 and screw conveyors 50 or packings 42aof baffle plate 37a, and to ensure continuous automatic cleaning of thefaces of packings 42a.

Screw conveyors 50 preceding pair of pinions 34 on the outlet side aredimensioned so as to overcome the resistance to flow of the twosucceeding baffle plates 37a and of pair of pinions 34.

On the inlet side pair of pinions 27 is succeeded in the direction offlow by tripartite distributing plate 60 whose structure is seen inparticular in FIG. 10.

Distributing plate 60 formed as a ring plate has a number of throughbores 61 lying on a common coaxial circle corresponding to the number ofsatellite shafts 23 for mounting it with little play on cylindricalcollar 62 (FIG. 2) of each satellite shaft 23.

In the space surrounded by the circle of through openings 61 there iscoaxial annular groove 63 opening upward from the plane surface, wherefor each through bore 61 side bore 64 originates lying on the sameradius therewith and leading as a through bore to the back ofdistributing plate 60. Annular groove 63 is limited on the radial insideby cylindrical inner seal ring 65 which is mounted in freely rotatablefashion on shaft jacket 18 and limits a narrow bearing gap on the othercircumferential side with annular groove 63.

Second outer seal ring 66 is placed with little bearing play on outercylindrical circumferential surface 67 of distributing plate 60. Itborders likewise with little play on the cylindrical inner surface ofhousing portion 4.

When satellite shafts 23 revolve about central shaft 17 seal rings 65,66 perform a rotary motion in opposite directions as indicated by arrowsin FIG. 10, which is imparted to them by frictionally engaged drive fromthe faces of the satellite shafts bearing spirals 24. The rotary motionin opposite directions comes about in the way clear from FIG. 11, whichalso shows that the two seal rings cover inner and outer wedge areas 70,71 between the housing and shaft jacket 18 as well as adjacent satelliteshafts 23.

As seen in particular from FIG. 2, the arrangement of side bores 64 onthe inside of through bores 61 of distributing plate 60 causes the sidebores to open directly within the particular satellite shaft ontospirals 24. This ensures a proper, precisely defined supply of materialinto the inside working chamber of each satellite shaft referred to as73 in FIG. 11, this working chamber being limited by shaft jacket 18 andspirals 24 of adjacent satellite shafts 23 as well as particularsatellite shaft 23 itself. During operation the so-called thick-layerside therefore lies in the area of inner working chambers 73.

Located opposite inner working chambers 73 is outer working chamber 74defined for each satellite shaft 23, being limited by housing jacket 4,spirals 24 of adjacent satellite shafts 23 and particular satelliteshaft 23 itself. In outer working chambers 74 the material to beprocessed is spread into thin layers, during operation, on the faces ofspirals 24 so that it is accessible to effective gassing and degassing,while at the same time being excellently homogenized and mixed whensuccessively and repeatedly passing through the narrow gaps betweenspirals 24 of adjacent satellite shafts. The side associated with outerworking chambers 74 is therefore the so-called thin-layer side of thering of satellite shafts or the whole apparatus.

The material to be treated is supplied to the treating means formed byspirals 24 on satellite shafts 23 via feeding means formed in coverplate 2 (compare FIGS. 1, 2). These feeding means contain ring channel75 disposed in cover plate 2 coaxially with central shaft 17 and havinga continuously decreasing axial height along its length starting fromlaterally disposed radial feed channel 76 for the material. Ring channel75 opens into annular groove 77 coaxial therewith which receives endpieces 51 of satellite shafts 23 with lateral play. During operation,satellite shafts 23 are therefore also embedded in the area of screwconveyors 50 on their faces in the material, which can flow to thespirals of screw conveyors 50 via laterally disposed grooves 77 onparticular end piece 51. Grooves 54 disposed on the faces improve thedistribution of material and prevent material from being deposited onthe faces of end pieces 51.

Screw conveyors 50 are dimensioned so as to overcome the resistance toflow which the material to be treated meets in baffle plates 37, pair ofpinions 27 and distributing plate 60.

Since central shaft 17 and satellite shafts 23 are supported axially andradially via pairs of pinions 27, 34 no separate axial support isprovided for this purpose in the area of cover plate 2. Central shaft 17passes through central cylindrical bearing opening 78 in cover plate 2whose diameter is selected so that it limits a thin bearing gap with thecylindrical outside wall of shaft jacket 18. In the area of bearing bore78 conveying thread 79 is applied to the outside of bearing jacket 18,protruding axially into the area of screw conveyors 50 on satelliteshafts 23 and having a pitch such that it constantly conveys, duringoperation, a certain amount of material in the axial direction throughthe bearing gap surrounding it in cover plate 2. This free-flowingmaterial filling the bearing gap seals the interior of the housingvacuum-tight from the outside.

To avoid vacuum losses through the annular gap between central shaft 17and shaft jacket 18, shaft jacket 18 is also sealed by two fitted sealrings 80, 81 against cylindrical journal 17a of central shaft 17. Thetwo seal rings 80 are braced axially by pressure screws 82, 83 acting oncorresponding thrust rings 84, 85.

Finally, heatable coaxial cooling ring 86 is placed on the outside ofcover plate 2, generally consisting of a very thermoconducting metal andbearing heating element 87 on its outer circumferential surface. Coolingring 86, which is bipartite for manufacturing reasons, has a coaxialring channel limited therein into which coolant connection 89 leads andwhich is limited on the radial inside by cooling ring member 86a weldedin liquid-tight fashion to outside cooling ring member 86b. Embodimentsare conceivable in which cooling ring members 86a, b are made ofdifferent materials in such a way that only inside cooling ring member86a is very thermoconducting.

In the area of its inside wall surrounding shaft jacket 18 with bearingplay, cooling ring 86 is provided with annular grooves 90 opening on theshaft side.

From ring channel 75 at least one side channel 91 branches off to openin cover plate 2 in the area of bearing bore 78 in the direct vicinityof cooling ring 86 and serving to bring free-flowing material from ringchannel 75 into the bearing gap between cooling ring 86 and bearing bore78 in cover plate 2 and shaft jacket 18.

Corresponding control of heating element 87 and the exposure to coolantat 89 hold cooling ring 86 during operation at a temperature which isbelow the melting point of the material to be processed, therebyensuring that the material filling the bearing gap can properly performits function as sealing means.

Conveying thread 79 on shaft jacket 18 can also be supplied withmaterial to be processed for purposes of rinsing from a side channel(not shown in FIG. 2) disposed opposite feed channel 76.

Between the two end portions on the inlet and outlet sides of theapparatus described with reference to FIGS. 2, 4 housing jacket 4 isdisposed, bearing substantially in the middle gassing or degassing meanswhich are illustrated in FIGS. 1, 3 and 7.

These gassing or degassing means have a gassing or degassing port whichis disposed in the area of the processing means formed by spirals 24 anddesigned as circumferential skewed slot 95. This skewed slot openingtoward the outside of housing jacket 4 is limited on both sides by conicwalling portions 96, 97 which enclose an acute angle with the axis ofcentral shaft 17 and are inclined toward the outlet side of theapparatus.

Skewed slot 95 opens on the outside into gassing or degassing chamber 98surrounding housing jacket 4 (FIG. 3) and limited by housing portions 99fastened to housing jacket 4 between which plane viewing glasses 100 areinserted in sealed fashion, resulting altogether in a square gassing ordegassing space. On one side connecting sleeve 101 is fitted in sealedfashion instead of a viewing glass, being surrounded by electric heatingelement 102 and connected to a vacuum or overpressure source. Dependingon the type of treatment for the material to be processed, it can alsolead to a collecting container or a condenser.

The described apparatus works as follows.

The material to be processed, for example a high-molecular moltenpolymer mass, fed continuously into ring channel 75 via feed channel 76at low pressure passes in the above-described way from ring channel 75to screw conveyors 50 on the inlet side which convey the materialthrough flow channels 41 of baffle plates 37 and pair of pinions 27 todistributing plate 60, from where the material is guided specificallyonto the radial inside of each satellite shaft 23 via side bores 64.

The thick-layer side thus forms within radially inside working chambers73 of threads 24 on satellite shafts 23, from where the material iscontinuously conveyed upon each revolution of the satellite shaftsthrough the gaps between meshing threads onto the opposite radialoutside, the thin-layer side, with working chambers 74 (FIG. 11).

The material conveyed in this way over the entire length of threads 24is continuously subjected to a vacuum for example (if the material is tobe degassed) on the outer thin-layer side via skewed slot 95 disposedapproximately in the middle between the inlet and outlet sides. Sincethe vacuum acts on the material spread in a thin layer with a largesurface area, an excellent degassing is obtained.

After the material passes through spirals 24 it is conveyed by screwconveyors 50 on the outlet side through baffle plates 37a and secondpair of pinions 34 into outlet channel 55, from where it reaches furtherprocessing means via connection 56.

In the described embodiment the length of satellite shafts 23 iscomparatively short (15 × the diameter of the satellite shaft) inconsideration of the necessary sojourn time of the material and thenumber of satellite shafts. Also, only one processing chamber ispresent, located between pairs of pinions 27, 34 in the area of spirals24.

As shown by FIG. 15, which illustrates the described embodiment of FIG.1 at a again for comparison, the apparatus can also be designed with amuch greater axial length, whereby a plurality of treating or processingchambers separated from one another by their own pairs of pinions andbaffle plates can also be disposed one axially behind the other.

Embodiments a, b thus show that a plurality of gassing or degassingmeans according to FIGS. 1, 3 can be provided over the length of theapparatus, each being equipped with its own gassing or degassing chamber98 according to FIG. 6 and corresponding connecting sleeve 101. Thecorresponding portions of the apparatus are designed as illustrated indetail in FIG. 3.

Between two such portions each containing gassing or degassing chamber98 the apparatus is divided by separate, preferably spur toothed pair ofpinions 110 into separate treating portions or chambers which aredisposed simply axially one behind the other. Central shaft 17 andsatellite shafts 23 are simultaneously supported radially againsthousing jacket 4 so that a proper shaft support with no excessivesagging of the shafts also results when the apparatus is disposedhorizontally.

As embodiments a and b of FIG. 15 show, one or more processing portionsor chambers can thus be connected in series for example.

The constructional design of the intermediate portions of the apparatuseach containing pair of pinions 110 is apparent from FIG. 16. Itcorresponds fundamentally to the formation of pair of pinions 34 asillustrated in FIG. 4.

Spur toothed central gearwheel 20 is placed on central shaft 17 so as torotate therewith, meshing with spur toothed pinion 36 which is placed soas to rotate therewith on accordingly serrated cylindrical part 330 of acorresponding portion of satellite shaft 23. The other spur toothed gear35 of pair of pinions 110 engages the internal toothing of annular gear9 fixed on the housing with which adjacent spacer ring 10 is associated.Between pinions 35, 36 there is baffle plate 37 whose flow channels 41are disposed as in FIG. 4.

Pair of pinions 110 is followed in the transport direction of thematerial by distributing plate 60 which is designed with two seal rings65, 66 according to FIG. 10 and guides the material via side bores 64 ineach case onto the inside, i.e. the thick side, of the followingportions of satellite shafts 23. This results in the same material feedconditions for the particular processing portion following pair ofpinions 110, as was already explained in detail for the first portion ofthe apparatus on the inlet side with reference to FIGS. 1, 2.

On the material feed side for pair of pinions 110 there is in each casebaffle plate 37a surrounded by housing ring 111 which is mounted insealed fashion between particular distance ring 9 and adjacent flange 13of corresponding housing jacket 4. Packings 42a of baffle plate 37a eachsurround screw conveyor 50 which is placed on cylindrical portion 331,provided with serration 31, of the preceding portion of satellite shaft23. Guide bush 52 effects mutual centering of the two coaxial satelliteshaft portions adjacent on the face.

The inflowing material from the preceding portion of particularsatellite shaft 23 (on the top in FIG. 16) comes past cleaning plates 58according to FIG. 12 into the area of screw conveyors 50, from where itpasses through flow channels 41a to pair of pinions 110. After flowingthrough pair of pinions 110 the material is guided, as explained above,through distributing plate 60 onto the thick-layer side of the lowerportion of satellite shaft 23.

Housing ring 111 has radial feed channel 112 formed therein which isconnected with flow channels 41a of individual satellite shaft 23 inbaffle plate 37a via ring channel 113 formed on the outside of baffleplate 37a and side channels 114 originating at ring channel 113. Feedchannel 112 thus opens into the area before pair of pinions 110; itpermits additive substances or materials to be introduced into thefollowing treating portion for conducting another treatment process, forexample admixture of a third substance.

I claim:
 1. An apparatus for continuously processing viscous liquids andmasses, in particular molten plastic masses and high-molecular polymers,having a number of axially parallel satellite shafts disposed in a ringwithin a housing and driven in the same direction via associatedpinions, said shafts bearing processing means engaging each other onadjacent satellite shafts and spreading the material to be processed ina thin layer in certain areas, a central shaft disposed in the center ofthe space surrounded by the satellite shafts and driven axially parallelto the satellite shafts, said central shaft bearing at least one drivinggear so as to rotate therewith, the satellite shafts being coupled ingeared fashion via their pinions with the central driving gear and withthe internal toothing of at least one annular gear fixed on the housingin such a way that when the central shaft rotates the satellite shaftsperform a common revolving motion about the central shaft, and feedingand removing means for introducing the material to be processed into therange of action of the processing means on the inlet side and removingit therefrom on the outlet side, characterized in that each satelliteshaft (23) bears at least two coaxial pairs of pinions (27; 34), onepinion (28; 36) of each pair of pinions engaging only a centralgear-wheel (19; 20) and the other pinion (29; 35) engaging only theinternal toothing of an annular gear (5; 9), and the pairs of pinions(27; 34) being spaced apart axially.
 2. The apparatus of claim 1,characterized in that the two pinions (28, 29) of at least one pair ofpinions (27) are provided with opposed helical toothings associated withcorresponding toothings on the particular central gearwheel (19) or onthe particular annular gear (5).
 3. The apparatus of claim 1,characterized in that the toothings of the pinions (28, 29) of one pairof pinions (27) are each formed with a module that results in anintegral number of teeth on the central gearwheel (19) or on theinternal toothing of the annular gear (5) from satellite shaft (23) tosatellite shaft (23).
 4. The apparatus of claim 1, characterized in thatthe pinions (28, 29; 35, 36) are connected with the satellite shafts(23) so as to rotate therewith by positive connecting means (31).
 5. Theapparatus of claim 4, characterized in that the connecting means have atoothing (31) with a module resulting in an angular pitch whose integralmultiple corresponds to the angular pitch between two adjacent satelliteshafts (23) and whose number of teeth is preferably divisible by four.6. The apparatus of claim 1, characterized in that the satellite shafts(23) bear in the area between the pairs of pinions (27; 34) on the inletand outlet sides at least one further pair of pinions (110) having acorresponding central gearwheel (20) and a corresponding annular gear(5) associated therewith.
 7. The apparatus of claim 1, characterized inthat at least one of the pairs of pinions (34; 110) is formed withpinions (35, 36), as well as a corresponding central gearwheel (20) anda corresponding annular gear (10), which each bear a spur toothing. 8.The apparatus of claim 1, characterized in that a baffle plate (37)having passages (41) for the material to be processed, which is coaxialwith the central shaft (17) and revolves about the central shafttogether with the satellite shafts (23), is disposed between the pinions(28, 29) of at least one pair of pinions (27) for each satellite shaft(23).
 9. The apparatus of claim 8, characterized in that the baffleplate (37, 37a) bears axially directed packings (42, 42a) whichsubstantially fill the wedge-shaped spaces between adjacent pinions (28,29; 35; 36) or screw conveyers (50) and the central shaft (17), as wellas the enveloping housing or housing portion.
 10. The apparatus of claim9; characterized in that the packings (42, 42a) are covered at least onthe face pointing toward the inlet side of the material to be processedat least partly by freely rotatable ring-shaped cleaning plates (58)which are coaxial with the central shaft (17).
 11. The apparatus ofclaim 1, characterized in that the satellite shafts (23) are connectedat least on the inlet side and/or on the outlet side with conveyingmembers (50) for the material to be processed.
 12. The apparatus ofclaim 11, characterized in that the conveying members are screwconveyers (50) which are each followed by a pair of pinions (27, 34,110).
 13. The apparatus of claim 12, characterized in that a baffleplate (37a) having passages (41a) for the material to be processed,which is coaxial with the central shaft (17) and revolves about thecentral shaft together with the satellite shafts (23), is disposed ineach case between the screw conveyers (50) and the following pinion (28;35) of the particular pair of pinions (27; 34).
 14. The apparatus ofclaim 1, characterized in that the satellite shafts (23) are ofmultipart design, their parts being interconnected so as to rotate withone another by coupling means (50, 31, 52).
 15. The apparatus of claim14, characterized in that it is divided into individual separatetreating portions or chambers limited at least on one side by pairs ofpinions (27, 110, 34), optionally with separate feeding means (112)leading thereinto, and being joined together axially.
 16. The apparatusof claim 14, characterized in that the coupling means are formed inpinions and/or in conveying members (50) adjacent thereto.
 17. Theapparatus of claim 1, characterized in that the feeding means for thematerial to be processed have at least one ring channel (75) connectedwith an inlet (76) and communicating with the satellite shafts (23) inthe area of their faces.
 18. The apparatus of claim 17, characterized inthat the ring channel (75) is formed with a height decreasingincreasingly from the inlet (76).
 19. The apparatus of claim 1,characterized in that the seal of the central shaft (17) from thehousing (1) has on the inlet side a cooling ring (86) surrounding it soas to form an annular gap and having means (88, 89; 87) for coolingand/or heating associated therewith, and the annular gap is subjected tothe material to be processed which can be held at a temperature belowits melting point by the cooling ring.
 20. The apparatus of claim 19,characterized in that the cooling ring (86) has ring-shaped coaxialgrooves (90) on the shaft side.
 21. The apparatus of claim 19,characterized in that the central shaft (17) is smooth in the area ofthe cooling ring (86) and has in the vicinity thereof conveying means(79) for supplying the annular gap with material to be processed whichcommunicate with its feeding means.
 22. The apparatus of claim 1,characterized in that the central shaft (17) is formed as a hollow shaftand can be heated by heating media inserted (21) or passed therein. 23.The apparatus of claim 1, characterized in that the central shaft (17)and/or the satellite shafts (23) are supported axially and radially onthe annular gears (5, 10) only via the central gearwheels (19, 20) andthe pinions (28, 29; 35, 36).